1. Field of the Invention
The present invention relates to shutter assemblies for whole house ventilation systems.
2. Prior Art
In the prior art there have been various attempts at making useful and operable shutter assemblies, and in certain instances, attempts have been made to provide for insulated shutters and shutter frames. U.S. Pat. No. 3,964,377 to Chapman (FIGS. 6 and 7) includes an illustration of what purports to be insulated shutters that are automatically operable, that is, moved to an opened position when the differential pressure across the shutters is sufficiently large. No mechanism is provided for sealing the shutters positively, and while seals are illustrated, there are gaps in the seals between the individual shutters; the shutters themselves are made so that they would conduct heat from one side of the closure to the other; and there is no means for applying any positive sealing force against the seals so that leakage is substantially uninhibited, even along the seal surfaces. Further, the adjacent edges of individual shutters are spaced forming an air infiltration gap of substantial magnitude. It should be also noted that the construction is shown in U.S. Pat. No. 3,964,377 so that there is a likelihood for binding between the adjacent shutters when they open or close.
The patents cited in U.S. Pat. No. 3,964,377 show various shutter constructions, but none appeared to be pertinent to the idea of providing automatically controllable insulated shutters. An insulated box or enclosure is disclosed in Flynn U.S. Pat. No. 3,583,171 (cited as a reference in U.S. Pat. No. 3,964,377) that is without automatic operation. Also, Bishop U.S. Pat. No. 3,123,098 cited in U.S. Pat. No. 3,964,377 shows a multiple louver damper which has individual shutter blades that carry seals at the outer edges and wherein sealing strips are installed along the hinge axis of each of the blades along the sides, again relying only on the blade weight for a sealing force. It further can be seen that the blades in Patent '098 are not insulated blades, and no positive seal force against the blades is provided.
U.S. Pat. No. 3,530,783 shows an inflatable damper seal that is held in place along the edges of the damper blade where the blades mate. A damper construction is shown in U.S. Pat. No. 3,605,603 including a plurality of pivoting noninsulated blades, and wherein the blades are made to attempt to provide a seal which engages during pivoting of the blades.
Streamlined or aerodynamic shutter blades are shown in U.S. Pat. No. 3,783,768 and also edge seals are illustrated in this particular patent. Again, no positive force can be applied to the blades and seals for positive sealing. The blades also are not constructed for maximum insulation purposes.
A similar type of pivoting shutter blade having vinyl seals along the side edges and at the hinge axis is shown in U.S. Pat. No. 4,038,781. The Scharres U.S. Pat. No. 3,084,715 shows pivoting shutter or damper blades that have resilient edges that engage each other for sealing purposes. Also there are seals at the ends of the unit, again with no apparatus which provides positive sealing forces.
U.S. Pat. No. 2,359,289 also shows a pivoting blade shutter assembly that has flexible seals along the ends of the shutter blades, and which does have a shutter operating lock that retains the shutters in either open or closed position. Light blocking shields are provided, but no teaching is made of providing a sealing arrangement for preventing air passage through the assembly.
Thus, in all of the prior art, there is no showing of a highly efficient insulated shutter assembly that provides for positive sealing of the shutter blades in a closed position to insure that heat transmission through the shutter is minimized during times when the shutter is not used for ventilation. The shutter assembly of the present invention is effective to prevent heat from infiltrating into the house during the time when air conditioning is being used and also to prevent heat from escaping from the house when the house is being heated.
The above patents primarily show the traditionally constructed thin metal louvers that provide a minimum air seal against back drafts and a barrier against insect or pest intrusion. These shutters all have relatively poor insulating qualities, and lack positive seals which permit the shutter assemblies to be used effectively in houses located in rather severe climate areas.